uu.seUppsala University Publications
Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Physiological recycling of endogenous nitrate by oral bacteria regulates gastric mucus thickness
Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Cell Biology.
Karolinska Inst, Dept Physiol & Pharmacol, Stockholm, Sweden..
Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Cell Biology.
Karolinska Inst, Dept Physiol & Pharmacol, Stockholm, Sweden..
Show others and affiliations
2015 (English)In: Free Radical Biology & Medicine, ISSN 0891-5849, E-ISSN 1873-4596, Vol. 89, 241-247 p.Article in journal (Refereed) Published
Resource type
Text
Abstract [en]

Background: Inorganic nitrate from exogenous and endogenous sources is accumulated in saliva, reduced to nitrite by oral bacteria and further converted to nitric oxide (NO) and other bioactive nitrogen oxides in the acidic gastric lumen. To further explore the role of oral microbiota in this process we examined the gastric mucus layer in germ free (GF) and conventional mice given different doses of nitrate and nitrite. Methods: Mice were given either nitrate (100 mg/kg/d) or nitrite (0.55-11 mg/kg/d) in the drinking water for 7 days, with the lowest nitrite dose resembling the levels provided by swallowing of fasting saliva. The gastric mucus layer was measured in vivo. Results: GF animals were almost devoid of the firmly adherent mucus layer compared to conventional mice. Dietary nitrate increased the mucus thickness in conventional animals but had no effect in GF mice. In contrast, nitrite at all doses, restored the mucus thickness in GF mice to the same levels as in conventional animals. The nitrite-mediated increase in gastric mucus thickness was not inhibited by the soluble guanylyl cyclase inhibitor ODQ. Mice treated with antibiotics had significantly thinner mucus than controls. Additional studies on mucin gene expression demonstrated down regulation of Muc5ac and Much in germ free mice after nitrite treatment. Conclusion: Oral bacteria remotely modulate gastric mucus generation via bioactivation of salivary nitrate. In the absence of a dietary nitrate intake, salivary nitrate originates mainly from NO synthase. Thus, oxidized NO from the endothelium and elsewhere is recycled to regulate gastric mucus homeostasis.

Place, publisher, year, edition, pages
2015. Vol. 89, 241-247 p.
Keyword [en]
Nitric oxide, Nitrosothiols, Gut microbiota, Nitrite, Ulcer
National Category
Physiology
Identifiers
URN: urn:nbn:se:uu:diva-274292DOI: 10.1016/j.freeradbiomed.2015.07.003ISI: 000366355800023OAI: oai:DiVA.org:uu-274292DiVA: diva2:897793
Funder
Torsten Söderbergs stiftelseSwedish Research Council, 08646
Available from: 2016-01-26 Created: 2016-01-20 Last updated: 2017-11-30Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full text

Authority records BETA

Phillipson, MiaHolm, Lena

Search in DiVA

By author/editor
Phillipson, MiaHolm, Lena
By organisation
Department of Medical Cell Biology
In the same journal
Free Radical Biology & Medicine
Physiology

Search outside of DiVA

GoogleGoogle Scholar

doi
urn-nbn

Altmetric score

doi
urn-nbn
Total: 496 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf